1. Field of the Invention
This invention relates to pumps and more particularly to an improved sonic pressure wave surface operated pump.
2. Description of the Prior Art
It is well known to provide a pumping mechanism at an underground level to pump liquid from that level to the surface, with such a down hole pump being operated by a surface located mechanism which reciprocally impacts a column of liquid contained within a tube that communicates between the surface located mechanism and the down hole pump. The surface located mechanism, in addition to impacting the column of liquid, is reciprocally operated to alternately open and close a liquid delivery port. The impaction of the standing column of liquid produces hydraulic pressure waves that are transmitted by the liquid to the down hole pump to impart a reciprocal movement thereto. The down hole pump includes a plunger, or similar mechanism, which is biased upwardly by suitable springs, and has a central passage formed axially therethrough with a one-way check valve located in the lowermost end of the passage. When the hydraulic pressure waves move the plunger down against the spring bias, the check valve opens to admit the liquid being pumped into the passage, and the subsequent upstroke of the plunger closes the check valve and causes a general upward movement of the standing column of liquid with the uppermost portion thereof exiting through the liquid delivery port formed in the surface located mechanism.
Examples of the above described pumping mechanisms, and others which operate on that same basic principle, are fully disclosed in U.S. Pat. Nos.: 2,379,539; 2,355,618; 2,572,977; 2,751,848 and 3,277,831.
These prior art pumps critically depend upon ideal adjustment of the input frequency relative to the length of the tube in which the standing column of liquid is contained, that is, resonant timing. Further, such prior art pumps are seriously limited in their pumping capacities due to such factors as inertia of the liquid, and the like.